Piano keyboard type electronic musical instrument having a bass pedal and single continuous keyboard



Aug. 12,1969 M15110 OMURA m1 3,461,217

PIANO KEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A- BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD med w. e, '1966 9 Sheets-Sheet 1 Tone Color 2U or M n 01 ,Cimults I I A u F/GI P/lb/Arf n1 Lower v v 1 /Amp'lfier Manuul I Tone Color Circuit Pedal C Lavier I Tone Generator Prior Ar! INVENTORS MASUO OMURA TAKAO ORITA MASAHIRO KOSAKA B1; MM A Aug. 12, 1969 MASUO OMU RA ET AL 3,461,217

" PIANO KEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD v 9 Sheets- -Sh eet 2 '2 Melody 5 M Tone Color Circuits Amplifier Ace-om pan-1 meat 3 7{Manual {6 l j/ 55* F IG. 4

Filed OCt. 6, 1966 'fone Color Circuit Tone I Genemior Osctllafor Frequency Divider INVENTORS MASUO OMURA TAKAO ORIT v A MASAHIRO KOSAKA ATTORNEYS Aug. 12, 1969 MASUO OMURA ET AL 3,461,217

PIANO KEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD Filed Oct. 6, 1966 9 Sheets-Sheet 3 INVENTORS MASUO OMURA VTAKAO 0mm 'MASAHIRO KOSAKA ATTORNEYS Aug. 12, 1969 MASUO QMURA ET AL 3,461,217

PIANO KEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD Filed 001,. 6, .1966 9 Sheets-Sheet 4 I A r115 \L I v 53 1 I L? 02 5 IDE 6 303 2 iA I INVENTOR$ MASUO OMURA TAKAO ORITA MASAHIRO KOSAKA BY tlwahazz; 142 MM Aug. 12, 1969 MASUO OMURA ET AL 3,461,217

PIANO KEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD Filed Oct. 6, 1966 N 9 Sheets-Sheet 5 FIG. 10

FIG. 11

INVENTORS MASUO OMURA TAKAO ORITA MASAHIRO KOSAKA BYWw M Arrolgysvs Aug. 12, 1969 MASUO OMURA ET AL 3,461,217

PIANQKEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD Filed Oct. 6, 1 966 9 Sheets-Sheet e |o| 43 ll \2 I. We 3 2 8/ I 412 I \J l v #I A2! l I "r '9:

24 7, L l l INVENTORS MASUO OMURA TAKAO ORITA MASAHIRO KOSAKA BY/JJA'M moms s Aug. 12, 1969 MASUO OMURA ET AL 3,461,217

PIANO KEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A I BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD Filed on. e, 1966 9 Sheets-Sheet 7 INVENTORS MASUO OMURA TAKAO ORITA MASAHIRO KOSAKA momsys Aug. 12, 1969 MASUQ QMURA ET AL 461,217

3. PIANO KEYBOARD TYPE ELECTRONIC MUSICAL IN UMENT HAVING A BASS PEDAL AND SINGLE CONTINUOUS YBOARD Filed Oct. 6, 1966 9 Sheets-Sheet 8 mvmons MASUO OMURA TAKAO ORITA MASAHIRO KOSAKA ATTORNEYS Aug. 12, 1969 MASUO OMURA ET AL 3,461,217

PIANO KEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD Filed on. e, 1966 e Sheets-Sheet 9 INVENTORS MASUO OMURA TAKAO ORITA MASAHIRO KOSAKA BYAJQMZ M ATTORNEY S United States Patent PIANO KEYBOARD TYPE ELECTRONIC MUSICAL INSTRUMENT HAVING A BASS PEDAL AND SINGLE CONTINUOUS KEYBOARD Masuo Omura, Hirakata-shi, Takao Orita, Suita-shi, and Masahiro Kosaka, Hirakata-shi, Japan, assignors to Matsushita Electric Industrial Co. Ltd., Osaka, Japan Filed Oct. 6, 1966, Ser. No. 584,737 Claims priority, application Japan, June 27, 1966, 41/42,483, 41/42,484

Int. Cl. Gh 3/00 U.S. Cl. 841.08 27 Claims ABSTRACT OF THE DISCLOSURE Conventional keyboard electronic musical instruments are generally divided into the following three groups: (1) an instrument having a piano type manual keyboard with white and black keys (this type keyboard will hereinafter be referred to as a manual keyboard), (2) an instrument having both a manual keyboard including double manuals and a pedal clavier, and (3) an instrument having both a manual keyboard and accompaniment chord buttons.

The instrument having a single manual keyboard of double manuals has usually been played by operating keys for producing melody notes with the right hand and operating keys for producing accompaniment notes with the left hand. However, it has been difficult to operate keys for producing bass notes in addition to playing accompaniment chords with the left hand at the same time.

Difficulty also arises in playing an instrument having both a manual keyboard including double manuals and a pedal clavier which enables control of the production bass notes with a foot.

In connection with an instrument having both a manual keyboard and accompaniment chord buttons, there exist other drawbacks, such as the fact that music scores arranged for the manual keyboard cannot be used with the chord buttons, and that with the chord buttons only a rather narrow variety of musical effects can be produced because players can play only predetermined accompaniment chords and bass notes.

It is an object of this invention to provide an electronic musical instrument which facilitates the playing of bass notes by adding a bass pedal for bass notes to a conventional instrument having a manual keyboard but having no pedal clavier.

A further object is to provide an electronic musical instrument which can give a rich musical expression and which sounds bass notes in a range wider than that which. can be sounded by a conventional instrument having a pedal clavier, by adding bass pedal means to the conventional accompaniment manual keyboard.

A further object is to provide an electronic musical instrument having a smaller size and a lower cost than a conventional instrument having a pedal clavier.

A further object is to provide an electronic musical instrument which makes it possible to use a music score 3,461,217 Patented Aug. 12, 1969 which is arranged for a conventional manual keyboard instrument.

Other objects will appear from the following description, reference being had to the accompanying drawings in which:

FIG. 1 is a block diagram of a circuit for a conventional instrument having manual keyboards and a pedal clavier;

FIG. 2 is a perspective view of an actual instrument shown diagrammatically in FIG. 1;

FIG. 3 is a perspective view of an electronic musical instrument according to this invention;

FIG. 4 is a block diagram showing an arrangement of the parts of one embodiment of said electronic musical instrument according to this invention;

FIG. 5 is a basic circuit diagram of one embodiment of an electronic musical instrument according to this inventlon;

FIG. 6 is a music score With an accompaniment which can be played by an electronic musical instrument as shown in FIG. 5; 1

FIG. 7 is a circuit diagram of a circuit which can be made at low cost to achieve the basic circuit diagram of FIG. 5;

FIG. 8 is another circuit of a circuit diagram which will produce the musical effects achieved by the circuit of FIG. 5;

FIG. 9 is a basic circuit diagram of a sec-0nd embodiment of an electronic musical instrument according to this invention;

FIG. 10 is a music score with an accompaniment which can be played by an electronic musical instrument as shown in FIG. 9;

FIG. 11 is a basic circuit diagram of a third embodiment of an electronic musical instrument according to this invention;

FIG. 12 is a circuit diagram of a circuit which can be made at low cost to achieve the musical effects achieved by the circuit of FIG. 11;

FIG. 13 is a music score with an accompaniment which can be played by the electronic musical instrument as shown in FIG. 12;

FIG. 14 is a block diagram of a circuit in which the bass pedal switch has been replaced by a gate circuit;

FIG. 15 is a diagrammatic view of an arrangement in which the bass pedal switch has been replaced by a light responsive element;

FIG. 16 is a basic circuit diagram of a fourth embodiment of an electronic musical instrument according to this invention;

FIG. 17 is a music score with an accompaniment which can be played by electronic musical instrument as shown in FIG. 16;

FIG. 18 is a circuit diagram of a circuit which facilitates changing decay times of sustain effects achieved by the circuit of FIG. 16;

FIG. 19 is a block diagram showing how the principal concept of this invention can be adapted for a conventional instrument having manual keyboards and a pedal clavier;

FIG. 20 is a circuit diagram illustrating a circuit for producing tone signals acording to this invention;

FIG. 21 and FIG. 22 are circuit diagrams illustrating circuits for producing tone signals having a more beautiful tone color than the tones produced by the circuit of FIG. 20; and

FIG. 23 is a circuit diagram of a circuit for a manual keyboard instrument in which multi-pole keyswitches can be operated by each of the keys.

Referring to FIG. 1, in a conventional manual keyboard type instrument, tone signals from a tone generator system 1 can be controlled by an upper manual 2, a lower manual 3 and a pedal clavier 4, and enter tone color circuits 5, 6 and 7, respectively, where they are mixed. Said three tone color circuits 5, 6 and 7 provide several different tone responses for melody notes, accompaniment notes and bass notes, respectively. The mixed tone signals are amplified by an amplifier 8, adjusted by a volume controller 9 with respect to their volume and then translated into sounds by a speaker 10 in a conventional manner.

Therefore, the conventional instrument having manual keyboards and a pedal clavier has a configuration as shown in FIG. 2, in which reference characters designate components having the same funtcions as those of FIG. 1. It is necessary for a player to operate an upper manual 2 with his right hand, a lower manual 3 with his left hand, a pedal clavier 4 with the left foot and a volume controller 9 with the right foot. It is difficult to play a pedal clavier 4 comprising more than twelve keys with the left foot. In addition, the conventional instrument is usually high in cost and large in size and is not convenient to transport.

The present invention contemplates the provision of a manual keyboard type instrument characterized by easy operation, small size, and the ability to produce a wide variety of musical effects.

Referring to FIG. 3, the novel instrument according to this invention includes a melody manual 12 on the right portion of a single continuous keyboard, an accompaniment manual 13 on the left portion, a volume controller 9 and a bass pedal 39. It is one of the features of this invention that a Single continuous keyboard is provided with both a melody manual 12 and an accompaniment manual 13 as shown in FIG. 3.

A schematic block diagram of the instrument is shown in FIG. 4 wherein the same reference characters as those of FIG. 1 designate the same components as those of FIG. 1. (The same reference characters will be used hereinafter to designate the same components.) Tone signals from a tone generator system 1 are controlled by a melody manual 12 and an accompaniment manual 13. The tone signals controlled by said melody manual 12 enter an amplifier 8 through a tone color circuit 5. One

part of tone signals cont-rolled by said accompaniment manual 13 behave as conventional accompaniment tone signals having pitches corresponding to each of the keys which have been actuated to produce them, and the signals of this part enter said amplifier 8 through a tone color circuit 6. Another part of the tone signals controlled by said accompaniment manual 13 behave as bass tone signals having a pitch which is lower by one or two octaves than that of said accompaniment tone signals corresponding to the keys which are actuated, and the signals of this part enter said amplifier 8 through bass pedal means 14 and a tone color circuit 7. It is a feature of this invention that said accompaniment manual 13 can control said accompaniment tone signals and said bass tone signals at the same time, and said bass pedal means 14 can control all of said bass tone signals produced by actuation of keys on accompaniment manual 13 so as to produce bass sounds rhythmically at the desired time.

According to this invention, the range of bass notes can be extended to the range of said accompaniment manual 13 whereas the range of conventional bass notes can be no greater than the range of a pedal clavier in the conventional instrument. The present invention has another advantage in that players can easily play bass notes singly by pressing a foot operated device, such as a bass pedal of said bass pedal means 14, rhythmically so as to sound the bass note.

Consequently, players can play the manual keyboard of the novel instrument in a way similar to that of a conventional instrument having only manual keyboards when said bass pedal means 14 is not operated, and can sound .4' tones are required. Therefore, the novel instrument can facilitate the usage of any music score arranged for a conventional instrument having manual keyboards.

An embodiment of this invention will be illustrated in connection with FIG. 5. An oscillator 40 oscillates at a frequency of the highest pitch of the note C which is to be played, and frequency dividers 41, 42 46, which are connected in series, generate tone signals at a frequency half of the oscillator 40 in the case of frequency divider 41, and half of the frequency of the preceding frequency divider in the cases of said dividers 42-46, respectively. An instrument according to this invention comprises numerous components such as dividers resistors, keyswitches and so on, but the description hereinafter will, for convenience, be restricted to typical ones. An oscillator 50 oscillates at a frequency of the highest pitch of the note B which is to be played, and dividers 51, 52, 53, etc., generate tone signals at successive half frequencies of the tone of said oscillator 50. There are further oscillators 60, 70, etc., and corresponding dividers 61, 62, etc., and 71, 72, etc., for the other notes.

In general, a tone generator system is divided into various groups, such as a group comprising oscillators and dividers or a group comprising separate oscillators for each tone signal. This invention has been presently illustrated, for example, with a group comprising oscillators and dividers, but it is applicable to any other possible tone generator system and should not be construed as being limited to an oscillator-frequency divider tone generating system.

The melody manual 12 has the same construction as that of the upper manual 2 of a conventional instrument as described in FIG. 1. Keyswitches of said melody manual 12 can switch tone signals for melody notes and thereafter said tone signals for melody notes enter an amplifier 8 through a tone color circuit 5 providing several different tone responses for the melody notes. Each key of the accompaniment manual 13 has two keyswitches coupled thereto so as to be simultaneously actuated by pressing an accompaniment manual key. For example, when the key C is pressed it actuates keyswitches 101 and 201, and when they key B is pressed it actuates keyswitches 102 and 202.

Keyswitches 101, 102 and 103 are coupled to dividers 43, 53 and 63, respectively, through resistors 111, 112 and 113, respectively. These keyswitches switch tone signals for accompaniment notes from the respective dividers 43, 53, and 63 corresponding to said keyswitches 101, 102 and 103 through resistors 111, 112 and 113, respectively, to said amplifier 8 through a tone color circuit 6 providing several different tone responses for the accompaniment notes. Said tone signals for accompaniment notes switched by keyswitches 101, 102 and 103 are thus controlled in the same manner as tone signals controlled by the lower manual 3 of a conventional instrument as shown in FIG. 1.

Keyswitches 201, 202 and 203 are double throw type keyswitches and form a lowest-tone-selecting-keyswitch system for selecting a tone signal corresponding to the lowest pitch among tone signals produced by simultaneously pressed keys. In said keyswitch system, a terminal 231 on the arm of keyswitch 201 is connected to the terminal 212 of keyswitch 202 which in contacted by the arm thereof in the unpressed state of the key corresponding thereto, and a terminal 232 on the arm of keyswitch 202 is connected to a terminal 213 of keyswitch 203 which is contacted by the arm thereof in the unpressed state of the key corresponding thereto, and so on.

The other terminal 221 of a keyswitch 201 is connected, through a resistor 241, to a frequency divider 44 which generates a tone signal for bass note having a pitch lower by one octave than that of the tone signal for the accompaniment note controlled by the keyswitch 101. The other terminal 222 of keyswitch 202 is similarly connected, through a resistor 242, to a frequency divider 54 which generates a tone signal for bass note having a pitch lower by one octave than that of the tone signal for accompaniment note controlled by the keyswitch 102. Keyswitches 203 and 204 are connected in the same manner. The keyswitch 204 is actuated by a key for the lowest pitch of said accompaniment manual 13. A terminal 234 of said keyswitch 204 is connected to a bass pedal switch 24 in bass pedal means 14, and said bass pedal switch 24 is connected to said amplifier 8 through a tone color circuit 7.

In the lowest-tone-selecting-keyswitch system made up of keyswitches 201, 202, 203 and so on, a switching action can be achieved by only the keyswitch actuated by the key of the simultaneously pressed keys in said accompaniment manual 13 which is for the lowest pitch tone. In this way, a player can select the lowest tone signal, which tone signal is switched again by a bass pedal switch 24 in said bass pedal means 14 into said amplifier 8 through said tone color circuit 7 which can produce several different tone responses for bass notes, such as tone colors and tone volumes suitable for bass notes, by changing the tone quality of said tone signal for a bass note.

By using a novel instrument having a circuit such as shown in the diagram, a player can play an accompaniment music score, for example, as shown in FIG. 6, part A, with the left hand operating said accompaniment manual 13 and with the left foot pressing the bass pedal of said base pedal means 14 in accordance with the rhythm of the rhythm score. Therefore, the player can produce bass tones rhythmically in addition to accompaniment chords of intermediate range in a music score as shown in FIG. 6B.

As a practical matter, it is preferable to generate a tone signal for bass note with a pitch lower by at least one octave than the pitch of a tone signal for an accompaniment note. For example, if said terminal 221 of the keyswitch 201, instead of being connected as shown, is connected through said resistor 241 to a frequency divider 45 which generates a tone signal for a bass note having a pitch lower by two octaves than the pitch of the tone signal for the accompaniment note generated by said divider 43, said keyswitch 201 switches into the amplifier 8 a tone signal for a bass note which has a pitch lower by two octaves than the pitch of the tone signal for the accompaniment note switched into the amplifier by said keyswitch 101. In a similar way to that described above, if each of said terminals 222, 223 and 224 is connected, through said respective resistors 112, 113 and 114 to the respective frequency dividers 55, 65 and 47, instead of as shown, each of said keyswitches 202, 203 and 204 can switch into the amplifier tone signals for bass notes having a pitch lower by two octaves than the pitch of the respective tone signals for accompaniment notes switched into the amplifier by the respective keyswitches 102, 103 and 104. Such a connection of the terminal to any desirable frequency divider can control the pitch of a tone signal for a bass note so that it is in the desired octave. This pitch control can also be achieved in a similar way for the various combinations of frequency dividers to be described hereinafter.

The musical effects in said music score shown in FIG. 6 can be achieved by a lower cost circuit made according to the circuit diagram shown in FIG. 7.

- Referring to FIG. 7, the keyswitches 101, 102 and 103 and the tone color circuit 6 are the same as the corresponding components in FIG. 5. Keyswitches 201, 202 and 203 are double throw keyswitches just as those in FIG. 5 and form a lowest-tone-selecting-keyswitch system for selecting the lowest tone. The terminal 221 of the keyswitch 201 is connected, through a resistor 241, to the frequency divider 43 which generates a tone signal for bass note having the same pitch as that of the tone signal for an accompaniment note switched to the amplifier by the keyswitch 101. The terminal 222 of the keyswitch 202 is connected, through a resistor 242, to the frequency divider 53 which generates a tone signal for bass note having the same pitch as that of the tone signal for the accompaniment note switched to the amplifier by the keyswitch 102. The same connection is made for keyswitches 203 and 204.

The terminal 234 of the keyswitch 204 which corresponds to the key for the lowest pitch note on the accompaniment manual .13 is connected to a binary divider means 31 for dividing a frequency by two or four. A bass tone signal divided by said binary divider means 31 has a pitch lower by one or two octaves than that of the undivided tone signal for the bass note. The binary divider means is connected to the bass pedal switch 24 which in turn is connected to the amplifier 8 through the tone color circuit 7. Therefore, each of said bass tone signals has a pitch lower by one or two octaves than the pitch of each of said tone signals for accompaniment notes.

The circuit shown in FIG. 7 produces the same musical effects as the circuit shown in the circuit diagram in FIG. 5, and has the advantage that there are fewer frequency dividers in the tone generator system, resulting in a less expensive tone generator system than in the circuit of FIG. 5.

The exact same musical effects can also be achieved in such a way that each of said double throw keyswitches 201, 202 and 203 switches a tone signal for bass note having a pitch higher by one or two octaves than the pitch of a tone signal for an accompaniment note switched into the amplifier by the respective keyswitches 101, 102 and 103. In this case, said binary divider means 31 must divide the frequency by four or eight. In addition, a base tone having a desirable pitch can be easily obtained by selecting a different dividing ratio of said binary divider means 31.

The musical effects achieved by the circuit according to the circuit diagram of FIG. 5 can also be produced at a lower cost by employing a circuit according to the diagram of FIG. 8.

Referring to FIG. 8, the key C actuates keyswitches 102 and 302, etc. The same arrangement is provided for keys Ait and C The components to which the keyswitches 101, 102 and 103, and the tone color circuit 6 are con-, nected are in the same arrangement and have the same function as in the circuit of FIG. 5.

In connection with the circuit diagram of FIG. 8, keyswitches 301, 302 and 303 are not double throw keyswitches but single throw keyswitches. Terminals 311, 312 and 313 of keyswitches 301, 302 and 303 are connected to ground. A terminal 321 for the arm of keyswitch 301 is connected to a terminal 322 for the arm of keyswitch 302 through a capacitor 331, and the terminal 322 is connected to a terminal 323 for the arm of keyswitch 303 through a capacitor 332. The terminals of the remaining keyswitches are connected in the same manner. Finally, an oscillator 32 is connected, through a capacitor 334, to a terminal 324 for the arm of keyswitch 304 which is actuated by the key for the lowest pitch tone of the accompaniment manual 13. Said oscillator 32 oscillates in such a way that its frequency varies with a change in a total capacitance between said oscillator 32 and the ground connection of said capacitors 331, 332, 333 and 304, said change being caused by actuating one of keyswitches 301, 302, 303 and 304. In addition, said frequency is at a pitch which corresponds to that controlled by the pressed key and is the same. as or different by one or more octaves from the pitch of the tone signal for the accompaniment note switched to the amplifier by said pressed key. In the case when some of the keyswitches 301, 302, 303 and 304 are actuated at the same time, said oscillator 32 oscillates a frequency having a pitch corresponding to a key for the lowest pitch tone controlled by the simultaneously pressed keys, because the total capacitance between said oscillator 32 and said ground for the capacitors 331, 332, 333

7 and 334 is determined by the keyswitch of simultaneously actuated keyswitches which is for the lowest tone. Therefore, these components form a lowest-tone-selecting-oscillator system.

A tone signal for a bass note from said oscillator 32 is divided by two, four or eight, by binary divider means 31 and enters amplifier 8 through the bass pedal switch 24 and the tone color circuit 7.

Said binary divider means 31 can be eliminated by using an arrangement in which said oscillator 32 oscillates so as to produce a tone signal for a bass tone having a pitch lower by one or two octaves than the pitch of said tone signal for the corresponding accompaniment note.

The same musical effects can be produced by modifying said oscillator 32 in such a way that the frequency varies with a change in the total resistance or inductance between said oscillator 32 and a ground for the resistors or inductors, so that such electrical elements can be substituted for said capacitors 331, 332, 333 and 334.

The circuit of FIG. 8 can produce the same musical effects as that of FIG. and is lower in cost because in the circuit of FIG. 8 there are fewer frequency dividers in the tone generator system and single throw keyswitches are used instead of the double throw keyswitches of FIG. 5.

The concept of this invention can be embodied in the basic circuit shown in the diagram of FIG. 9.

Referring to FIG. 9, the circuit is the same as that of FIG. 5, except that the keyswitches 301, 302, 303 and 304 are single throw switches and the terminals for the arms thereof are connected in parallel to the bass pedal switch 24. In this case a player can play one or more bass notes at a time because keyswitches 301, 302 and 303 do not form a lowest-tone-selecting-keyswitch system for selecting the lowest tone. Each of the tone signals for bass notes switched by the respective keyswitches 301, 302 and 303 is combined and again switched by the bass pedal switch 24 into the amplifier 8 through the tone color circuit 7.

By using a novel instrument having such a circuit, a player can play accompaniment for a music score shown in FIG. A with the left hand operating the accompaniment manual 13 with the left foot pressing the bass pedal of the bass pedal means 14 in accordance with a rhythm of a rhythm score, so that he can produce rhythmic bass notes in addition to accompaniment chords of intermediate range in the music score shown in FIG. 10B. The circuit of FIG. 9 produces musical effects differing a little from those achieved by the circuit diagram of FIG. 5, but produces at least musical effects sought to be achieved by the present invention.

The concept of this invention can be embodied in a further basic circuit shown in FIG. 11.

Referring to FIG. 11, the key C closes keyswitch 101, and the key B closes keyswitch 102. Keys Ait and C act similarly as described above. Keyswitches 101, 102 and 103 in this embodiment are single pole keyswitches. The keyswitch 101 switches a mixture of a tone signal from the divider 43 for an accompaniment note corresponding to said key C and a tone signal from the divider 44 for a bass note having a pitch lower by one octave than the pitch of the accompaniment tone signal to the amplifier 8, the mixture of the signals being obtained by impedance elements such as resistors 111 and 241. The keyswitch 102 switches a mixture of a tone signal from the divider 53 for an accompaniment note corresponding to said key B and a tone signal from the divider 54 for a bass note having a pitch lower by one octave than the pitch of the accompaniment tone signal to the amplifier 8, said mixture of the signals being obtained by resistors 112 and 242. Keyswitches 103 and 104 likewise switch a mixed signal to the amplifier. The outputs from switches 101, 102, 103 and 104 are connected in parallel to the tone color circuit 6 and bass pedal switch 24.

The combined tone signals enter the amplifier 8 through 8 the tone color circuit 6 and are also switched to the amplifier by the bass pedal switch 24 through the tone color circuit 7. In this embodiment said tone color circuit 6 has a low frequency cut-off filter means and produces several different tone responses such as tone colors and tone volumes which are suitable only for accompaniment notes of intermediate range, and said tone color circuit 7 has a low frequency pass filter and produces several different tone responses such as tone colors and tone volumes which are suitable only for bass notes. Tone signals from said tone color circuit 7 essentially have pitches lower by one octave than the pitches of tone signals from said tone color circuit 6. Therefore, the circuit of FIG. 11 can produce musical effects almost the same as those produced by the circuit of FIG. 9.

The circuit of FIG. 11 can be simplified as shown in FIG. 12.

Referring to FIG. 12, keyswitches 101, 102 and 103 are the same as those of FIG. 11. The keyswitch 101 switches to the amplifier only a tone signal from the divider 43 which is handled so as to serve both as an accompaniment note and bass note corresponding to a key C and the keyswitch 102 switches to the amplifier only a tone signal from the divider 53 which serves both as an accompaniment note and a bass note corresponding to a key B Keyswitches 103 and 104 operate to switch only one tone signal in the same way. The outputs of said keyswitches 101, 102, 103 and 104 are connected in parallel to tone color circuit 6 and bass pedal switch 24.

The combined tone signals enter the amplifier 8 through the tone color circuit 6, and are also switched by a bass pedal switch 24 through a tone color circuit 7 to the am plifier 8. Said tone color circuit 6 produces several different tone colors and tone volumes which are suitable only for accompaniment notes, and said tone color circuit 7 includes a high frequency cut-out filter and produces several different tone colors and tone volumes which are suitable only for bass notes. The volume of said bass notes is usually larger than that of said accompaniment notes.

By using the novel instrument having such a circuit, a player can play the accompaniment of a music score as shown, for example, in FIG. 10A with the left hand operating the accompaniment manual 13 and with the left foot which presses the bass pedal of bass pedal means 14 in accordance with a rhythm of a rhythm score, so that he can rhythmically produce in addition to the accompaniment chords of intermediate range the bass notes as shown in the music score of FIG. 133. The circuit as shown in the diagram in FIG. 12 produces musical effects differing a little from those achieved by the circuit shown in FIG. 11, but can produce at least the musical effects which it is desired to produce by this invention.

A more effective and more practical foot-operated bass pedal means can be obtained by modifying the bass pedal switch 24 illustrated in FIGS. 5, 7, 8, 9, 11 and 12. A tone signal for bass note switched to the tone color circuit directly by said bass pedal switch 24, as shown in those figures, is apt to give the bass tone envelope a sudden attack and a sudden decay, and to result in a slightly undesirable bass tone.

Referring to FIG. 14, said bass pedal switch 24, illustrated in FIGS. 5, 7, 8, 9, 11 and 12, can be replaced by a gate circuit 33 which can control the output level of tone signals for bass notes by a change in a controlling voltage or current and can switch the tone signal indirectly so as to produce a desirable bass tone. A power supply 11 is connected, through a pedal switch 25 and a resistor 15, to said gate circuit 33 and to both a capacitor 16 and a resistor 17 which are connected in parallel to ground. Said pedal switch 25 is closed by pressing a foot-operated device, such as shown at 39 in FIG. 15, and simultaneously the voltage for controlling said gate circuit 33 rises at a rate depending upon the time constants of said resistors 15, 17 and said capacitor 16. The decay .of the control voltage depends upon the time constant of the capacitor 16 and the resistor 17 when said pedal switch 25 is switched 01f. In such a way, the output level of said gate circuit 33 has an attack time and a decay time corresponding to the rising and decay time of the controlling voltage so as to produce a desired bass tone.

The bass pedal switch 24 illustrated in FIGS. 5, 7, 8, 9, 11 and 12 can be modified to provide a more practical circuit in a dilferent way from that shown in FIG. 14.

Referring to FIG. 15, the bass pedal switch 24 of FIGS. 5, 7,8, 9, 11 and 12 .is replaced by a light responsive element 34, such as a CdS cell, the resistance of which varies with the intensity of the light which falls thereon. A foot operated device, such as a bass pedal 39 pivotally actuates a shutter 36 through a tie rod 37 and controls the intensity of light from a lamp 35 so as to control the volume of the tone signals for bass notes. Therefore, the amount said bass pedal is depressed controls said volume. Such a device can easily control the attack and decay of the bass tones and also the amplitude of the bass tone signals so as to produce effective bass tones. Variable impedance devices such as variable resistor can act as said light responsive element 34 and achieve the same effect as that mentioned above.

Another arrangement according to this invention can produce a bass tone which has a gradual decay such as will produce a sustain effect, by means of the circuit of FIG. 16.

Referring to FIG. 16, the key C actuates keyswitches 101, and 201, and the key B actuates keyswitches 102 and 202 keys A and C likewise actuate their corresponding keyswitches. Components connected by said keyswitches 101, 102 and 103 and the tone color circuit 6 are the same means as in FIG. 5. Said switches 210, 20 2 and 203 are double throw switches and are connected in a lowest-tone-selecting-keyswitch system for selecting the lowest tone in the same way as in the circuit described in FIG. 5. The terminal 221 of said keyswitch 201 is connected to a gate circuit 271 and to a capacitor 251 and a resistor 261, which are connected in parallel to ground. The terminal 222 of said keyswitch 202 is connected to a gate circuit 272 and to a capacitor 252 and a resistor 262 which are connected in parallel to ground. Keyswitches 203 and 204 are connected to gate circuits 273 and 274 in the same manner.

Said gate circuit 271 is connected between frequency divider 44 and tone color circuit 7 and controls the passage of a tone signal for a bass note having a pitch lower by one octave than the pitch of the tone signal for the accompaniment note switched to the amplifier 8 by said keyswitch 101. Said gate 272 .is connected between frequency divider 54 and tone color circuit 7 and controls the passage of a tone signal for a bass note having a pitch lower by one octave than the pitch of the tone signal for the accompaniment note switched to the amplifier 8 by said keyswitch 102. Gate circuits 273 and 274 are similarly connected. The tone signals for the bass note controlled by each of the gate circuits 271, 272, 273 and 274 are combined. The combined tone signals for the bass notes are fed into the amplifier 8 through a tone color circuit 7. A power supply 11 for controlling said gate circuits 271, 272, 273 and 274 is connected, through a single pedal switch 25 and a resistor 15, to the terminal 234 of the keyswitch 204 corresponding to a lowest key on the accompaniment manual 13.

In operation, when keys C and Ait are pressed, for example, they actuate keyswitches 101, 201 and 103, 203, and therefore, keyswitches 101 and 103 are closed so as to produce tone. signals for accompaniment notes corresponding to said keys C and A11 The pedal switch 25 is switched on by pressing a foot operated. device, such as a bass pedal 39, in a succession of pedal actions. Therefore, said gate circuit 273is supplied, through the resistor 15 and keyswitch 204, the arm of which is up in contact with terminal 214, and keyswitch 203, the arm of which is down in contact with terminal 213, with a controlling .voltage from power supply 11 so as to permit passage of a tone signal for bass note having a pitch lower by one octave than that of a tone signal for the accompaniment note corresponding to said key A# During this time, said keyswitch 201 of said key C has been actuated but the contact point 213 of said keyswitch 203 is open, which prevents said gate circuit 271 from being supplied with said controlling voltage from power supply 11. Therefore, no bass note corresponding to said key C appears at tone color circuit 7.

When said pedal switch 25 is switched off, said controlling voltage in said capacitor 253 discharges slowly through the resistor 263, and said gate circuit 273 is closed slowly over a period of time depending upon said discharging control voltage. When said keys C and A11 are released, said tone signals for accompaniment notes switched on by said keyswitches 101 and 103 stop the sounding of said accompaniment notes. However, said tone signal for bass note corresponding to said key A0 keeps sounding during the gradual decay which is obtained by said gate circuit 273 since said capacitor 253 still retains said controlling voltage.

In such a way, the arrangement defined by FIG. 16 can produce bass tones having gradual decays, in other words, sustain effects, in accordance with this invention.

By using a novel instrument having such a circuit, a player can play an accompaniment music score as shown, for example, in FIG. 17A with the left hand operating an accompaniment manual 13 and with the left foot pressing the bass pedal in accordance with a rhythm of a rhythm score. Accordingly, the player can rhythmically produce bass notes in addition to accompaniment chords of an intermediate range as shown in the music score in FIG. 17B.

A device according to this invention can control the duration of the sustain effects of the bass tones produced by the circuit illustrated in FIG. 16.

Referring to FIG. 18, the capacitor 251 coupled with the gate circuit 271 is connected to one end of a diode 291 through a resistor 281, the capacitor 252 coupled with the gate circuit 272 is connected to one end of a diode 292 through a resistor 282, and the capacitor 253 coupled with the gate circuit 273 and the other capacitors are similarly connected. The other ends of said diodes 291, 292 and 293 are connected in parallel to a variable resistor 29 which controls a voltage from a bias power supply 38. Each of said resistors 281, 282 and 283 is less than the respective resistors 261, 2 62 and 263.

When a voltage obtained through said variable resistor 29 is higher than the voltages to which each of said charged capacitors 251, 252 and 253 have been charged, said diodes 291, 292 and 293 are in a reverse polarity and open the circuit to said power supply 38. Therefore, the discharge of each of said capacitors 251, 252 and 253 is controlled only by the respective resistors 261, 262 and 263 and a long decay time is provided. When the voltage obtained through said variable resistor 29 is slightly lower than the voltages of the charged capacitors 251, 252 and 253, said capacitors 251, 252 and 253 discharge through said resistors 281, 282 and 283, respectively, until the voltage of each of said capacitors 251, 252 and 253 equals the voltage obtained through said variable resistor 29, and thereafter said capacitors 251, 252 and 253 discharge only through said resistors 261, 262 and 263 so as to provide an intermediate decay time. A short decay time also can be provided by causing capacitors 251, 252 and-253 to discharge through said resistors 281, 282 and 283 by making the voltage obtained through said variable resistor 29 zero or near zero.

It is easy to control the decay times so as to produce sustain effects for tone signals which are controlled by said gate circuits 271, 272 and 273 by means of time constant circuits when the voltage obtained through said variable resistor 29 can be controlled manually.

The conception of this invention can also be adapted for an electronic musical instrument equipped with con- 11 ventional manual keyboards of the piano type and a conventional pedal clavier.

Referring to FIG. 19, reference character 1 designates a tone generator system, 2 is an upper manual, 5, 6 and 7 are tone color circuits, 8 is an amplifier, 9 is a volume controller and 10 is a speaker, all of which parts correspond to the instrument as described in FIG. 1. A lower manual 3 corresponds to the accompaniment manual 13 illustrated in FIG. 4 according to this invention, and controls at the same time both tone signals for accompaniment notes and tone signals for bass notes.

A pedal clavier 4 controls tone signals for bass notes in a conventional way, and simultaneously a bass pedal switch 24 built into said pedal clavier 4 controls tone signals for bass notes already controlled by said lower manual 3 in accordance with this invention. Said bass pedal switch 24 is attached to one or more, or all of said pedal clavier keys independently of the conventional pedal keyswitches. A double throw switch 19, when it is in contact with the terminal 21 permits playing in a manner similar to that for playing a conventional musical instrument having manual keyboards and a pedal clavier, and when it is in contact with the terminal converts the instrument to a novel instrument according to this invention.

Difficulty in playing bass notes by means of said pedal clavier 4 can be eliminated by using said bass pedal with said switch 19 contacting said terminal 20. In such a way the concept of this invention can be easily applied to a conventional electronic musical instrument having manual keyboards and a pedal clavier.

Tone signals having a beautiful tone color can be obtained by employing a divider in a flip-flop type circuit according to this invention.

Referring to FIG. 20, reference character 90 designates an oscillator and 91, 92 and 93 are frequency dividers employing a flip-flop circuit. The tone signal from said divider 92 is switched by a keyswitch 902 through a reistor 912 and produces a tone Signal having a wave form 902a. The tone signal from said divider 93 is switched by a keyswitch 903 through a resistor 913 and produces a tone signal having a wave form 903a, and said divider 94 produces a tone signal having a wave form 9040] in a similar way. Said wave forms 902a, 903a, and 904a contain harmonics in an odd number and are suitable for preparing a tone color characteristic of a woodwind instrument.

A tone color differing from that of a woodwind instrument can be obtained by employing an arrangement shown in FIG. 21 or 22 according to this invention.

Referring to FIG. 21, reference character .90 again designates an oscillator and 91, 92 and 93 are frequency dividers having a flip-flop type circuit. The outputs of each frequency divider, in addition to being fed to the respective switches 902, 903, etc., are also fed to the output of the next lower tone signal frequency divider through resistances 922, 923, 924, etc. The tone signal switched by a keyswitch 902 through resistors 922 and 912 is thus a mixture of the tone signals of said dividers 91 and 92. The mixing ratio can be controlled by a proper choice of said resistor 922 and 912. For example, the tone signal switched by keyswitch 902 has a wave form 9021) with a mixing ratio of the tone signal of divider 91 to the tone signal of divider 92 of 1:2. Tone signals switched by keyswitches 903 and 904 produce wave forms characterized by said mixing ratios in a similar way. Tone signals having wave forms 902b, 903b and 904b contain harmonics in both even and odd numbers and produce more satisfactory sounding tones than the tone signals having wave forms 902a, 903a and 904a do.

Referring to FIG. 22, the circuit is the same as in FIG. 21 except that there are added connections from the outputs of each frequency divider to the output of the next higher tone signal frequency divider through resistances 931, 932, 933, etc. The tone signal switched by keyswitch 902 through resistors 922, 912 and 932 is thus a mixture of the tone signals of said dividers 91, 92 and 93'. The mixing ratio can be controlled by a proper choice of said resistors 922, 912 and 93 2. When the mixing ratio is, for example, 112:1 for the tone signals of dividers 9'1, 92 and 93, respectively, the tone signal at said keyswitch 902 has the wave form 902C. Tone signals at keyswitches 903 and 904 have wave forms 9030 and 9040, respectively, which are produced in a similar way to that of wave form 902a. It will be readily understood that wave forms 902e, 903a, and 9040 produce more satisfactory musical effects than do Wave forms 902b, 903i) and 904b.

A harmonics of a tone signal can be improved extensively by using a mixture of tone signals from various dividers or oscillators in a proper mixing ratio as illustrated in FIGS. 21 and 22, said mixture being able to act as a tone signal generated by a divider, such as one of aforesaid tone signals for accompaniment notes or one of aforesaid tone signals for bass notes, in accordance with this invention. This method of mixing tone signals for obtaining a beautiful tone color can be applied to any other tone generator system, even one which does not have flip-flop type dividers.

The concept of this invention can also be applied to a conventional electronic musical instrument having a double manual keyboard and no pedal clavier by modifying the instrument slightly in such a way that the upper manual keyboard and the lower manual keyboard act as the melody manual :keyboard and the accompaniment keyboard, according to this invention, respectively, and a foot-operated bass pedal means is added.

In addition, the concept of the accompaniment manual keyboard according to this invention can be applied to a part of an accompaniment manual or lower manual for producing musical effects of bass notes by a range of tone signals for bass notes.

Furthermore, the concept of this invention can be applied to an electronic musical instrument in which each key of the manual keyboard actuates more than two keyswitches at the same time.

Referring to FIG. 23, the key C actuates four keyswitches 401, 101, 501 and 201 at the same time, and the key B actuates four keyswitches 402, 10-2, 502 and 202 at the same time. Keys Ait and C similarly actuate four keyswitches. Keyswitches 101, 102 and 103 are single throw switches and switch tone signals for accompaniment notes from dividers 43, 53 and 63 corresponding to keys C B and A0 respectively, to the amplifier 8. Keyswitches 401, 402 and 403 are single throw switches and switch tone signals for accompaniment notes from dividers 42, 52 and 62, which are higher by one octave,

than the tone signals for the accompaniment notes switched by keyswitches 101, 102 and 103, respectively. Keyswitches 501, 502 and 503 are also single throw switches and switch tone signals for accompaniment notes from dividers 44, 54 and 64, which are one octave lower than said tone signals for accompaniment notes switched by keyswitches 101, 102, and 103 respectively. Each of the output sides of keyswitches 401, 402 and 403 is connected to the tone color circuit 6 through a tone switch 16. Each of the output sides of keyswitches 101, 102 and 103 is connected to the tone color circuit 6 through a tone switch 17, and each of the. output sides of keyswitches 501, 502 and 503 is connected to said tone color circuit 6 through a tone switch 18.

A lowest-tone-selecting-keyswitch system including double throw tkeyswitches 201, 202 and 203, foot operated bass pedal means 14 including a bass pedal switch 24 and a tone color circuit 7 are connected in the same manner as the circuit of FIG. 5. Each of said keyswitches 201, 202 and 203 switches tone signals for bass notes generated by dividers 45, 55 and 65, through resistors 241, 242 and 243, respectively, to the bass pedal means 14, so that each of said tone signals fora bass note is 13 lower by two octaves than the tone signals for accompaniment notes generated by dividers 43, 53 and 63, respectively.

In such a way the novel concept of this invention can be applied to any electronic musical instrument of the piano keyboard type, in which a manual keyboard controls tone signals for tones which are one octave apart.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the forms hereinbefore described and illustrated in the drawings being merely preferred embodiments thereof.

What is claimed is:

1. An electronic musical instrument of the piano keyboard type, comprising, in combination: a tone generator system for generating tone signals capable of producing melody notes, tone signals capable of producing accompaniment notes and tone signals capable of producing bass notes; a melody manual keyboard coupled to said tone generator system and having keys for controlling the output of said tone signals for melody notes from said tone generator system; an accompaniment manual keyboard coupled to said tone generator system and having keys for controlling the output of said tone signals for accompaniment notes from said tone generator system, at least some of said keys on said accompaniment manual keyboard simultaneously controlling the output of signals from said generator for producing bass notes having a pitch which is related to the pitch of said tone signals for accompaniment notes by a whole number multiple of octaves; bass pedal means coupled to the output of said at least some of said keys for controlling said tone signals for bass notes; three tone color circuits, one coupled to each of the outputs of said manual keyboards and the third being coupled to the output of said base pedal means, and which provide tone responses for melody notes, accompaniment notes and bass notes, respectively, and an amplifier and sound reproducing means to which the outputs of said tone color circuits are coupled.

2. An electronic musical instrument as claimed in claim 1 wherein both said melody manual keyboard and said accompaniment manual keyboard are part of a single continuous keyboard.

3. An electronic musical instrument as claimed in' claim 1, wherein said bass pedal means includes a footoperated bass note pedal and means for controlling the amplitude of the tone signals for bass notes in response to the movement of said bass note pedal, whereby the volume of said tone signals for the bass notes varies with the amount said foot-operated bass pedal is moved.

4. An electronic musical instrument as claimed in claim 1, whereinsaid bass pedal means comprises a footoperated bass pedal, .a circuit including a variable resistor through which the bass tone signal passes, and means coupledto said bass pedal and actuated in response to movement thereof for varying the resistance of said variable resistor for varying the strength of the bass note signal and hence the volume of the bass notes when said foot-operated bass pedal is moved. 1

'5. An electrical musical instrument as claimed in claim 1, wherein said bass pedal means comprises a footoperated bass pedal, acircuit including a light responsive resistance element through which the bass tone signal passes, and means coupled to said base pedal and actuated in response to movement thereof for varying the light striking saidresistance element for varying the strength of the bass note signal and hence the volume of the bass notes when said foot-operated bass pedal is moved.

6. An electronic musical instrument as claimed in claim 1, wherein said bass pedal means comprises a footoperated bass pedal, a circuit including a variable impedance element through which the base tone signal passes, and means coupled to said bass pedal and actuated in response to movement thereof for varying the impedance of said variable impedance for varying the strength of the bass note signal and hence the volume of the bass notes when said foot-operated bass pedal is moved.

- 7. An electronic musical instrument as claimed in claim 1 wherein said bass pedal means comprises a gate circuit coupled between the output from said keys controlling bass note signals and said tone color circuit for bass notes, a source of power for actuating the gate circuit, and a foot-operated bass pedal switch coupled between said source of power and said gate circuit.

8. An electronic musical instrument as claimed in claim 1, wherein said bass pedal means has a single footoperated base pedal for actuating said bass pedal means.

9. An electronic musical instrument as claimed in claim 1, wherein said bass pedal means comprises a pedal clavier having a plurality of foot-operated bass pedal keys each controlling one of the tone signals for bass notes transmitted directly 'from said tone generator system, said accompaniment manual keyboard being coupled to said pedal clavier for feeding said tone signals for bass notes controlled by keys on said accompaniment manual keyboard to at least one of said bass pedal keys, and switch means between said pedal clavier and said third tone color circuit for switching to the third tone color circuit the group of tone signals for bass notes transmitted directly from said tone generator system and controlled by said bass pedal keys or the group of tone signals for bass notes controlled by said accompaniment manual keyboard and controlled by said bass pedal keys so as to supply only a selected group of tone signals for bass notes to said third tone color circuit.

10. An electronic musical instrument as claimed in claim 1, having keyswitches for each of the keys on said melody manual keyboard for switching melody notes from said tone generator system to the corresponding tone color circuit, and having a first set of keyswitches for each of the keys on said accompaniment manual keyboard for switching tone signals for accompaniment notes from the tone generator system to the corresponding tone color circuit, and a further set of keyswitches for said at least some of the keys on said accompaniment keyboard manual for switching tone signals for bass notes from said tone generator system to said bass pedal means, said further set of keyswitches being connected in parallel to said bass pedal means.

11. An electronic musical instrument as claimed in claim 1 having keyswitches for each of the keys on said melody manual keyboard for switching melody notes from said tone generator to the corresponding tone color circuit, and having a single set of keyswitches, one for each of the keys on said accompaniment manual keyboard for switching tone signals for accompaniment notes from said tone generator system to the corresponding tone color circuit, said keyswitches of said single set being coupled to said tone generator system for switching bass tone signals and being connected in parallel both to said tone color circuit for said accompaniment tone signals and to the bass pedal means, said accompaniment tone color circuit having a filter for filtering out low frequency components of tone signals, and said bass tone color circuit having a filter for passing low frequency components of tone signals.

12. An electronic musical instrument as claimed in claim 1 having keyswitches for each of the keys on said melody manual keyboard for switching melody notes from said tone generator to the corresponding tone color circuit, and having a single set of keyswitches, one for each of the keys on said accompaniment manual keyboard and coupled to said tone generator system for switching only a single tone signal, said keyswitches of said single set being connected in parallel both to said tone color circuit for said accompaniment tone signals and to the bass pedal means, and said bass tone color circuit having a filter for filtering out high frequency components of tone signals.

13. An electronic musical instrument as claimed in claim 1 in which at least some of the outputs of signals from said tone generator system are coupled to the outputs of signals for tones one octave lower and are mixed with said signals for tones one octave lower.

14. An electronic musical instrument as claimed in claim 1 in which at least some of the outputs of signals from said tone generator system are coupled to outputs of signals for tones one octave lower and are mixed with said signals for tones one octave lower, and resistances being provided in said coupled outputs for controlling the mixing ratio of said signals.

15. An electronic musical instrument as claimed in claim 1 in which at least some of the outputs of signals from said tone generator system are coupled to the outputs of signals for tones one octave lower and to the outputs of signals one octave higher and are mixed with said lower and higher signals.

16. An electronic musical instrument as claimed in claim 1 in which at least some of the outputs of signals from said tone generator system are coupled to the outputs of signals for tones one octave lower and to the outputs of signals one octave higher and are mixed with said lower and higher signals, and resistances being provided in said coupled outputs for controlling the mixing ratio of said signals.

17. An electronic musical instrument as claimed in claim 1, wherein said bass pedal means includes time constant circuit means for controlling the amplitude of tone signals for bass notes in such a way that the attack time and decay time of said tone signals for bass notes are made less abrupt.

18. An electronic musical instrument as claimed in claim 17 wherein said bass pedal means comprises a gate circuit coupled between the output from said keys controlling bass note signals and said tone color circuit for bass notes, a source of power for actuating the gate circuit, and a foot-operated'bass pedal switch coupled between one side of said source of power and said gate circuit, and said time constant circuit comprises at least one resistor and one capacitor connected in parallel and coupled between the other side of said power source and the connection between said gate circuit and said switch.

19. An electronic musical instrument as claimed in claim 1 having keyswitches for each of the keys on said melody manual keyboard for switching tone signals for melody notes from said tone generator system to the corresponding tone color circuit, and having a first set of keyswitches for each of the keys on said accompaniment manual keyboard for switching tone signals for accompaniment notes from the tone generator system to the correspondingtone color circuit, and a further set of keyswitches for said at least some of the keys on said accompaniment keyboard manual for switching tone signals for bass notes from said tone generator system to said bass pedal means, said further set of keyswitches being connected to each other in a lowest-tone-selectingkeyswitch system for switching only the tone signal for a bass note which corresponds to the lowest key of a plurality of simultaneously pressed keys on said accompaniment manual keyboard.

20. An electronic musical instrument as claimed in claim 19, wherein said further set of keyswitches is coupled to said tone generator system for controlling tone signals for bass notes having a pitch lower by at least one octave than the pitch of the tone signals for the accompaniment notes controlled by the keys controlling the respective keyswitches of said further set of keyswitches.

21. An electronic musical instrument as claimed in claim 19 wherein said bass pedal means includes a binary frequency divider means for lowering the pitch of the tone signal for a bass note which is initially switched by said lowest-tone-selecting-keyswitch system.

22. An electronic musical instrument as claimed in claim 21, wherein said binary frequency divider means has means forming a part thereof for selecting the dividing ratio of said binary divider means.

23. An electronic musical instrument of the piano keyboard type, comprising, in combination: a tone generator system for generating tone signals capable of producing melody notes, tone signals capable of producing accompaniment notes and tone signals capable of producing bass notes; a melody manual keyboard coupled to said tone generator system and having keys for controlling the output of said tone signals for melody notes from said tone generator system; an accompaniment manual keyboard coupled to said tone generator system and having keys for controlling the output of said tone signals for accompaniment notes from said tone generator system; keyswitches for each of the keys on said accompaniment manual keyboard for switching tone signals for accompaniment notes from the tone generator system; three tone color circuits, one coupled to the otuput of said melody manual keyboard for providing tone responses to melody notes, a second being coupled to the output of said keyswitches for providing tone responses for accompaniment notes, and a third being for providing tone responses for bass notes; a plurality of connections between said tone generator system and said third tone color circuit for conducting tone signals for bass notes to said third tone color circuit, each of said connections having a gate circuit therein; a power supply for said gate circuits; a foot-operated bass pedal switch coupled between said source of power and said gate circuits; a further set of keyswitches actuated by keys in said accompaniment manual keyboard, one for each gate circuit, and coupled to each other and to said pedal switch for supplying power to the gate circuit through the keyswitch operated by the key on the accompaniment keyboard for the lowest tone; and amplifier and sound reproducing means to which the outputs of said tone color circuits are coupled.

24. An electronic musical instrument as claimed in claim 23 and further including a time constant circuit coupled to each said gate circuit between the corresponding keyswitch and said gate circuit and comprising at least one resistor and one capacitor in parallel and having the other ends thereof coupled to said power source.

25. An electronic musical instrument as claimed in claim 24 and further including means for varying the time delay provided by said, time constant circuit and comprising a further power supply, a variable resistance coupled to said power supply, and a diode and an impedance means coupled between said, variable resistance and the end of said parallel resistance and capacitance circuit coupled to each said gate circuit.

26. An electronic musical instrument of the piano keyboard type, comprising, in combination: a tone generator system for generating tone signals capable of pro.- ducing melody notes, and tone signals capable of producing accompaniment notes; a melody manual keyboard coupled to said tone generator system and having keys for controlling the output of said tone signals for melody notes from said tone generator system; an accompaniment manual keyboard coupled to said tone generator system and having keys for controlling the output of saidtone signals for accompanimentnotes from said tone generator system; keyswitches for each of the keys on said accompaniment manual keyboard for switching tone signals for accompaniment notes from the tone generator system; three tone color circuits, one coupled to the output of said melody manual keyboard for providing tone responses to melody notes, a second being coupled to the 17 output of said keyswitches for providing tone responses for accompaniment notes, and a third being for providing tone responses for bass notes; a bass pedal means in the input to said third tone color circuit; a variable frequency oscillator having the output coupled to said bass pedal means; a plurality of keyswitches which are coupled in parallel to said oscillator for actuating said oscillator and are positioned for being actuated by the keys on said accompaniment manual keyboard; and amplifier and sound reproducing means to which the outputs 10 of said tone color circuits are coupled, said oscillator producing only the tone signal for a bass note corresponding to the lowest key of a plurality of simultaneously pressed keys on said accompaniment manual keyboard and having a pitch which is related to the pitch of said tone signals for accompaniment notes by a whole number multiple of octaves.

18 27. An electronic musical instrument as claimed i: claim 26 and having a binary frequency divider mean coupled between said oscillator and said bass pedal mean:

References Cited UNITED STATES PATENTS 3,040,612 6/1962 Dorf 84-1.08 1 3,176,060 3/1965 Bissonette et al. 841.0

HERMAN KARL SAALBACH, Primary Examiner PAUL L. GENSLER, Assistant Examiner US. Cl. X.R. 841 

